[Solved] Why does this Python code raise an error when executed on Raspberry Pi?import sqlite3 conn = sqlite3.connect('data.db') cursor = conn.cursor() cursor.execute('SELECT * FROM sensor_data') print(cursor.... | Raspberry Pi

Raspberry Pi - Data Logging and Databases

Why does this Python code raise an error when executed on Raspberry Pi?

import sqlite3
conn = sqlite3.connect('data.db')
cursor = conn.cursor()
cursor.execute('SELECT * FROM sensor_data')
print(cursor.fetchall())
conn.close()

Assuming the table sensor_data has not been created yet.

AThe table 'sensor_data' does not exist in the database

BThe fetchall() method is called before execute()

CThe database file 'data.db' cannot be opened

DThe connection is closed before executing the query

Step-by-Step Solution

Solution:

Step 1: Understand the error cause
Executing SELECT on a non-existent table causes an OperationalError in SQLite.
Step 2: Verify code logic
The code tries to query 'sensor_data' which is not created, so SQLite raises an error.
Final Answer:
Table 'sensor_data' does not exist -> Option A
Quick Check:
Check table creation before querying [OK]

Quick Trick: Create tables before querying them [OK]

Common Mistakes:

MISTAKES

Querying tables before creating them
Assuming database file exists with required tables
Closing connection prematurely

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Why does this Python code raise an error when executed on Raspberry Pi?

Step 1: Understand the error cause

Step 2: Verify code logic

Final Answer:

Quick Check:

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